Post any defects you find in the released or beta versions of the ImageMagick software here. Include the ImageMagick version, OS, and any command-line required to reproduce the problem. Got a patch for a bug? Post it here.

Seems I made a mistake when I refactored the code. Just pushed a fix to our github repository to resolve this. This is an IM6 OpenCL issue, switching to IM7 or disabling OpenCL for now will resolve your issue.